IDE knowledge anyone?

Oliver Lehmann lehmann at
Sun Dec 6 15:14:39 CST 2015

Jon Elson <elson at> wrote:

> On 12/06/2015 02:57 PM, Oliver Lehmann wrote:
>> Hi,
>> I've built a Harddisk-Controller-Emulator for my system which accesses
>> a IDE (PATA) harddisk with an ATMega in PIO mode. It works like a charm
>> except for one WD harddisk. The harddisk itself works fine with MS-DOS
>> 6.22 and FreeBSD but refuses to work with my ATMega.
>> On reading or writing a sector, right after the command is issued, the
>> error bit is set in the status register, and the error register indicates
>> an ABRT.
> I don't have any specific knowledge of this, but it has to be a  
> timing problem.
> Something about the timing of the command signals is just different  
> enough that the drive thinks this is wrong.  Sorry I can't give more  
> specific help.

Thought the same and added some 400ns sleeps between each of the cylinder,
sector, head commands and before I executed the read command... without
success :(

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